HELLENIC AIR FORCE ACADEMY
Early Warning
against
Stealth Aircraft,
Missiles, and UAVs
Wg Cdr Konstantinos C. Zikidis HAF
Electronics Engineer, Ph.D. MIET
The effects of the absence of early warning
RCS vs Range for APG-68(V)9
RCS vs Range for APG-68(V)9
POFACETS: RCS prediction with the help of
computational electromagnetics (Physical Optics)
Reference Image Processing
F-35 3D modelling
in Blender 3D
RCS polar diagram for the F-35 model
seen from 10° below, at 10 GHz
estimated RCS, front sector
(-45° to +45° in azimuth,
-15° to +15° in elevation):
0.1 m² (w/o RAM)
0.01 m² (with RAM)
Reminder:
0.0015 m² is the RCS value
“leaked” by USAF
This procedure was applied to the F-16 and DF-15,
yielding plausible results, confirming our approach
AUTODESK 3ds MAX
est. frontal RCS:
0.5 m² (w/o RAM)
@10GHz
CATIA v5
est. frontal RCS:
0.002 m² (w/ RAM)
@10GHz
0.05 m² (w/o RAM)
@150MHz
Average RCS of the F-35 vs frequency
for the front sector (from -45° to +45°) and overall view,
averaged from -15° to +15° in elevation
F-16 vs F-16
APG-68(V)9: RCS 1 m² @ 38 n.m., F-16 RCS: 1.2 m²
F-16 vs F-35
APG-68(V)9: RCS 1 m² @ 38 n.m., F-16 RCS: 1.2 m²
APG-81: RCS 1 m² @ 82 n.m., F-35 RCS: 0.01 m²
APG-83:
RCS 1 m² @ 70 n.m.
F-16 vs F-35
APG-68(V)9: RCS 1 m² @ 38 n.m., F-16 RCS: 1.2 m²
APG-81: RCS 1 m² @ 82 n.m., F-35 RCS: 0.01 m²
APG-83:
RCS 1 m² @ 70 n.m.
Average RCS of the SOM (Stand-Off Missile)
vs frequency for the front sector (from -45° to +45°)
IEEE/NATO Radar bands
from http://radartutorial.eu
Radar coverage of the HADR or HR-3000 radar
against a target with RCS of 1 m²
Radar coverage of 4 HR-3000 radars against a
target with RCS of 1 m²
Radar coverage of the HADR or HR-3000 radar
(S-band) against the F-35
Radar coverage of the HADR or HR-3000 radar
(S-band) against the F-35
Radar coverage of 4 HR-3000 radars (S-band)
against the F-35
Radar coverage of the Marconi S743D radar
(L-band) against the F-35
Radar coverage of the Marconi S743D radar
(L-band) against the F-35
Radar coverage of 4 Marconi S743D radars
(L-band) against the F-35
Low frequency band radars: VHF/UHF/L-band
Stealth designs are optimized for medium to high freq. bands
Wavelength is comparable to aircraft parts (wings, stabilators)
Scattering enters Mie or resonance region (max RCS)
RAM is less effective at low frequencies
VHF radars cannot be detected by HARM or Harpy weapons
Transportable, 3D
AESA VHF Radar
1L119 NEBO SVU
(Rosoboronexport,
Russia)
Low frequency band radars
transportable, digital design, modern semiconductor
technology, designed for low RCS targets
2D VHF Radar JY-26 "Skywatch-U"
VOSTOK E 3D V/UHF-Band Radar
(Agat/KB Radar, Belarus) (China)
Coming back to the West...
Thales SMART-L EWC
(Early Warning Capability)
L-band radar w/ ABM
(Land/Naval/Mobile)
ELM-2090U ULTRA-C1:
Mobile Air Defence and
Early Warning UHF Radar
IAI-ELTA ELM-2090U UHF
ULTRA Early Warning radar
Multistatic radars: transmitters and receivers at
different places
Passive radars (passive coherent location – PCL):
no transmitter – various receivers, exploiting disturbance on
existing RF transmissions (TV, FM, GSM, HDTV...)
Pros: no transmission, so no license required, use of low
frequency bands (better stealth detection), detection even at
very low altitude, cannot be detected and targeted...
Cons:
uncontrolled RF
transmissions,
no detection
at high altitudes,
2D tracking
Lockheed Martin
Silent Sentry 1999
Passive radars (passive coherent location – PCL)
Thales Homeland
Alerter 100
Transportable
passive radar
by Airbus Defence and
Space (ex Cassidian)
CELLDAR – CELL PHONE RADAR (BAE Systems – Roke, UK),
AULOS Passive Covert Location Radar (Leonardo, Italy),
Various approaches based on SDR technology
InfraRed Search & Track (IRST) Systems
Stealth aircraft employ techniques for IR signature reduction,
as well. However, a fast jet cannot disappear in the IR band...
Better angular resolution
No direct range measurement
Passive operation – cannot be jammed
Missile seekers (e.g., MICA IIR, IRIS-T)
EADS Eurofighter:
PIRATE (Passive Infra
Red Airborne Tracking
Equipment)
by EUROFIRST
FLIR, IRST, up to 200
targets, at 50 – 90 km
F-16 vs F-35
APG-68(V)9: RCS 1 m² @ 38 n.m., F-16 RCS: 1.2 m²
APG-81: RCS 1 m² @ 82 n.m., F-35 RCS: 0.01 m²
IRST at MFOV, at high altitude, behind the target
APG-83:
RCS 1 m² @ 70 n.m.
Modern E/O and IRST (US)
LM Legion Pod / IRST 21
AN/AAQ-32 IFTS
NG Open Pod
Modern InfraRed Search & Track (Europe)
Rafale OSF: IRST, Eurofighter PIRATE: IRST, FLIR.
FLIR, TV, Laser.
Gripen Skyward:
IRST
Modern InfraRed Search & Track (Russia)
PAK-FA IRST
SU-35 IRST Su-27ULB with
OLS-27
Conclusions
Stealth technology has become sine qua non: all
military aircraft, tanks, ships etc, are designed or
redesigned according to low observable techniques
Stealthiness is not panacea: stealth aircraft are not
invincible.
It seems not possible to confront stealth aircraft
employing only one radar/sensor technology
A promising approach relies on the following:
– Low freq. radars for med-high altitude surveillance
– Passive radars for low-med altitude surveillance
– Data fusion of all sensors through networking
– Aircraft control and track designation via data link
– Onboard IRST systems for detection and tracking
Thank you for your attention !
Yorkshire Air Museum, Elvington, York
https://gr.linkedin.com/in/konstantinos-zikidis-32485430
